A general consensus of numerous epidemiological studies is that altered plasma lipoprotein levels is a significant risk factor for the incidence and severity of cardiovascular diseases (CHD). Apolipoproteins (apo). structural components of lipoproteins. have also been described as risk factors for CHD. As a ligand for the low density lipoprotein (LDL)- receptor, apo B is of strong interest as an atherogenic factor. This interest has led to several investigations of the effect of apo B gene polymorphism on ligand and lipoprotein levels in several ethnic groups including Caucasians, Japanese, Chinese and Nigerians. In the present project we will test the hypothesis that genetic variation in apo B affects variability in plasma quantitative traits in African Americans. Specific activities will be conducted to test the hypothesis include: 1. Establish a registry consisting of 2000 randomly selected unrelated African American subjects between the ages of 18 and 65 who are residents of 12 Black Belt counties in Alabama; 2. Collect data on the study participants in the registry: Risk factors for CHD including lip, lipoprotein, apolipoprotein levels: other demographic variable including age, gender, weight, height, and other life style characteristics: 3. Determine within the individuals in the registry, the distribution of apo B haplotypes defined by recombinant DNA analysis: and 4. Conduct statistical analysis of the impact of apo B on lipid and lipoprotein levels in African Americans from the black-belt counties of Alabama. The results of the proposed work will provide evidence as to the impact of apo B gene polymorphism on difference in plasma risk factors for CHD in African Americans. As an incentive for participation, participants will receive nutritional education intervention using the Pen-3 Model to reduce the risk of developing CHD or, if already present effects of the disease. The work will also provide evidence necessary to determine if previously published reports of the significance of apo B as a CHD risk factor in Nigerian blacks can be extended to American blacks. The registry of individuals from the 12 Black Belt counties in Alabama will provide a useful resource for scientists interested in cohort studies of CHD and other diseases in African Americans.